v1 boundary for the Mac App Store subset. Folds the floating piano panel into a single liquid-glass popover and trims everything behind the cutoff. UI / layout: - Fold the instrument cluster (qwerty + arrows + chooser) into the popover as one column; retire the floating two-column panel. - Popover backdrop is now NSGlassEffectView on macOS 26 (legacy vibrancy fallback) with a continuous arrow+body mask; embedded cluster skips its own glass so surfaces don't double. - Recessed "ground" plate behind the qwerty map AND the arrow cluster. - Remove the volume slider, the top-right octave readout, and the REC dot. - About: drop the percussion-split, cassette-deck, and pedals controls. Pitch-bend: - Fix trackpad pitch-bend: drop the unreliable NSTouch `trackpadTouchActive` gate (it never fired through the popover's key window, so the gesture never engaged) and gate on `keyboardNotesHeld || shift`. Original mouse-hide bug stays fixed — mouse taps use the tap channels, not keyboardNotesHeld, so a plain pointer move can't bend or hide the cursor. Global keys: - The double right-⌘ tap is now the ONLY system-wide key. The ⌥ percussion taps are local-only, and the focus/exit/layout/piano-waveform/percussion RegisterEventHotKey bindings are unregistered. Layout + percussion still toggle from the local key handler while Menu Band is focused. Other: - Linger fade no longer resurrects a faded note on melodic-channel reuse. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>